HOMEWORK 4 – 2019 Exercise 1. Using the Mayer-Vietoris exact sequence compute the homology groups of the sphere with two handles. Exercise 2. Consider a surface which consists of the disk to which the Moebius band is attached in such a way that we stick the boundary of the Moebius band (homeomorhic to S1 ) to the boundary of the disk. Using the Mayer-Vietoris exact sequence compute the homology of this surface. (In fact, this is the projective plane.) 1